Accumulator in refrigerant system



y 1957 D. F. SWANSON 2,799,999

ACCUMULATOR IN REFRIGERANT SYSTEM Filed April 16, 1956 INVENTOR Donald F Swanson ATTORNEY ACCUTVIULATOP. IN REFRIGERANT SYSTEM Donald F. Swanson, St. Paul, Minn.

Application April 16, 1956, Serial No. 578,375

Claims. (Cl. 62-115) This invention relates to an improvement in flooded refrigerant system and deals more particularly with a system in which the liquid cooling medium is permitted to circulate within the evaporator coil.

An object of the present invention lies. in increasing the coil efficiency of an evaporator coil by maintaining the entire coil circuit at the evaporating refrigerant temperature. This is accomplished by providing a column of liquid capable of continuously circulating the refrigerant in the coil.

A feature of the present invention lies in the provision of an accumulator having a center tube extending therethrough which is connected between the capillary tube and the body of the evaporator coil. This tube is arranged vertically to provide a column of liquid therein. A vent opening is provided within the accumulator near the top of the through tube and a second small opening is. provided through the center tube near the lower extremity of the accumulator. A certain amount of liquid refrigerant and gas enters the accumulator near the upper end thereof and tends to equalize the pressure in the center tube and in the body of the accumulator. In this way a column of liquid is produced which provides sufiicient pressure to force intermittent slugs of gas and liquid through the evaporator coil.

A feature of the present invention lies in the fact that liquid refrigerant is fed into the evaporator coil so as to provide spaced slugs of liquid interspersed with areas of gas. As the liquid evaporates throughout the length of the evaporator coil, a more constant temperature is maintained throughout the length thereof. Circulation of the liquid and gas is insured by the weight of liquid in the accumulator acting upon one end of the evaporator coil.

This application is a continuation in part of my previously filed application, Serial No. 247,797, filed September 22, 1951, now abandoned.

These and other objects and novel features of my invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of my specification:

The figure illustrates diagrammatically the refrigerant system embodying the accumulator and refrigerant supply tube extending therethrough.

With reference to the drawing, the numeral 10 designates a compressor of any suitable type, the outlet 11 of which is connected to a condenser 12. The compressed refrigerant gases are condensed in the condenser 12 and are forced under some pressure through the capillary tube 13. This capillary tube 13 is connected as indicated at 14 through a refrigerant loop 9 to a center tube 15 extending through an accumulator 16.

The accumulator 16 comprises a sealed tubular body restricted at its upper end as indicated at 17 to seal about the inlet connection 14. The center tube 15 may be of somewhat larger diameter than the capillary tube. This center tube having a size of, for example, 1 of an inch in outside diameter. The accumulator tube body 16 ited States Patent 9 is of somewhat larger diameter, as for example one inch. The, lower end 19 of the tubular body 16 is sealed about the. center tube 15. in, any suitable manner.

A vent hole 20 is provided in the through tube or center tube 15 near the upper end of the accumulator body and within this body 16. A refrigerant feed hole 21 extends through the center tube 15- near the lower extremity of the accumulator body. The proportion of these apertures will be later described in detail. In one arrangement of my construction the holes 29 andv 2 1 were approximately 91 of an inch in diameter. The holes vary in'size in proportion with, the size of compressor used and have been made as small as about 9 of an inch and as large as of an inch.

The evaporator coil, 22 is. connected to the lower end of the center tube 15 and this coil is formed of any suitable shape and. length, thev extremity of the coil being connected at 23 to the accumulator body 16. The tube 22 preferably extends through the wall of the accumulater 16 and the extremity of the tube may be bent downwardly so as to direct liquid downwardly into the accumulator body.

The suction line 24 of the compressor 1% is provided with an extremity 25 extending through the wall of the accumulator 16 near the upper end thereof. The extremity 25 is preferably bent out of direct alignment with the coil extremity 23 so that fluid entering the accumulator from the evaporator coil will not tend to pass directly into the suction line 24 through the line extremity 25.

The operation of my refrigerant system is as follows:

The gaseous refrigerant is compressed in the compressor 10 and is forced into. the condenser 12 which cools and liquifies the refrigerant. The liquid refrigerant is forced through the capillary tube 13 which is preferably in heat exchangev relation with the suction line 24 of the compressor. The refrigerant then passes through the connection 14 and into the upper extremity of the center tube 15 in the accumulator 16.

A certain amount of liquid and gaseous refrigerant vents into the interior of the accumulator 16, tending to equalize pressure within the center tube 15 and outwardly thereof within the accumulator body 16; There is more tendency for gaseous refrigerant to vent through the opening 20 than for the liquid refrigerant to be forced therethrough. Accordingly, a column of liquid is built up in the through tube 15 which is virtually solid. Gaseous voids in the column 15 may be partially replaced by liquid within the accumulator outwardly of the center tube, this liquid draining into the center tube 15 through the feed hole 21.

The gaseous and liquid refrigerant passes into the coil 22 and provides intermittent slugs of liquid and gas in the coil. The accumulator is so constructed and arranged as to provide a liquid column of suflicient height and weight to force the refrigerant completely through the evaporator coil. This task is facilitated by the evaporation of the refrigerant and accordingly, the change in density of the refrigerant within the evaporator coil. In any event the refrigerant in the evaporator coil gradually evaporates and the weight of liquid in the center tube 15 is sufiicient to maintain a constant flow of refrigerant through the coil.

The refrigerant passing completely through the evaporator coil 22 flows into the upper end of the accumulator. The liquid refrigerant drains downwardly in the space exteriorly of the center tube 15 while the gaseous refrigerant is free to flow through the suction line 24 and into the compressor 1% to start a new cycle of operation. As the amount of liquid exteriorly of the center tube 15 increases, the tendency for the liquid refrigerant to flow through the feed hole 21 and into the evaporator coil is increased and the height of liquid within the center tube 15 is maintained. In any event the weight of liquid in the accumulator is at all times suflicient to maintain the flow of refrigerant through 'theevaporator coil during operation of the system. i i V It will be noted thatthe evaporator coil 22 will be maintained at a substantially constant temperature due to the circulation of liquid refrigerant through the coil, the liquid refrigerant gradually evaporating and the size'of the gaseous voids between the slugs of liquid increasing. At the end of the evaporator coil most of the liquid has evaporated and the portion of the refrigerant still in liquid form flows into the accumulator and is recirculated through the coil. 1

While the arrangement described is believed the best arrangement, the system has been operated, though less successfully, with the topvent hole 20 omitted. The weight of the liquid refrigerant causes it to flow into the lower end of the tube 15 through the feed hole 21, tending to fill up gaseous voids in the tube 15. f Some gaseous refrigerant may vent through the passage 21, bubbling through the liquid refrigerant.

In accordance with the patent statutes, I have described the principles of construction and operation of my 're frigerant system, and while I have endeavored to'set forth the best embodiment thereof, I desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention;

' I claim: 1

1. A refrigerant system includingacornpressor, a condenser connected thereto to liquify the refrigerant, a re stricted passage conn'ectedte said condenser, a downwardly extending tube connected to said restr ictedpassage, an evaporator coil connected to the lower end of said tube, a housing encircling said tube and sealed at its lower end thereabout, said coilbeing connected to said housing near the upper end'thereof, and a suction line connected to-said housing near the upper end thereof, and said tube having restricted openings therethrough within said housing near the upper and lower ends there'- 4 in said tube and within said accumulator near the upper end thereof through which gaseous refrigerant may pass, and a second restricted opening in said tube and within said accumulator near the lower end thereof through which liquid refrigerant may flow, said coil communicating with the upper end of said accumulator, and a suction line also communicating with the upper end of said accumulator. q I t 7. A refrigerant system including an evaporator coil, an upright tube connected at its lower end to said'c'oil, an accumulator encircling said tube, a restricted feed opening in said tube and within said accumulator near the lower end thereof through which liquid refrigerant accumulated in said accumulator may flow into said upright tube, a compressor, a suction line connecting said compressor to the interior of said accumulator near the upper end thereof, a restricted connection connecting the compressor to said upright tube, and said evaporator coil c'ommunicatingwith' the interior ofsaid accumulator near the upper end thereof; j I H p 8. A refrigerant system includingafc'ompressor, a condenser connected-thereto to liquify-the refrigerant, a restricted-passage connected to said condenser, afmember forming-a downwardly 'extendin'gtubular passage connected to said restricted passage, an evaporator coil connected to the lower end'of said tubular-passage, an accumulator housingattachedto" 's'aid member. forming a tubular passage and sealed at itsupper and lower ends, said coil being connected-to said housing near the upper end thereof, a suction line connected 'to' said housing near the upper end thereof and communicating with the interior thereof, said-membe'r forming a tubular passage having a restricted opening providing 'a communicating passagebetween said 'tubular passage and said housing near the lower end thereof, said'opening 'near' the lower end of said housing acting to permit liquid refrigerant in said housing to drain into saidtubular passage.

of, the opening at the upperend acting as a vent for gaseous refrigerant;

2. The structure de'scribedin claim l andin which the housing is sealed'to said tube at its upper extremity; a

' 3 The structure described-inclaim l and in which the coil end -and the ;suction;line extend into said'housing in off-set relation I a 4. A refrigerantsystem includin'g'an evaporator coil,

an upright tube connected at its lower end idone'iend ings therethrough near the upper and lower ends of said accumulator housing, means for urging refrigerant downwardly in said tube, the opening at the upper end. acting as a vent for gaseous refrigerant. 1

5. The structure described in claim 4 and including a suction line connecting said housing to said means for forcing refrigerant.

6. A refrigerant system including an evaporator coil, an upright tube connected at its lower end to said coil, an accumulator encircling said tube, a restricted opening of said coil, anaccumulator housing encircling said tube," the enclosed portion of said tube having restricted open- 9.. 'Ihe structure of claim Sand including a restricted vent passagecorinecting'said housing and said tubular passage near theupper'end thereof through which gaseous refrigerant may vent from said tubular passage into said housing. I I

10. A refrigerant system including 'amember forming a downwardly extending tubular passage, an evaporator coil connected to the lowerend of said passage, an accumulator housing attached to said member forming a tubular passage and sealed at its upper and lower ends,

said coil being connected to said housing near the upper end thereof, a suction line connected to said housing near U the upper end thereof, means for forcing refrigerant downwardly through. said passage, said means forming a tubular passage having a restricted opening providing a communicating passage between said tubular passage and said housing near the lower end thereof, said opening acting to permit liquid refrigerant in said housingto drain into said tubular passage.

References Cited in the file of this patent UNITED STATES PATENTS 

